58 



SEA-SHORE LIFE 



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Fig. r,o: BASKET STARFISH. Tortiigas, FlorMa. 



with a tough skin. The basket star feeds upon unlucky fishes 

 which may seek a retreat within the branches of the trellis, only to 



be seized and devoured. 

 It is found along our 

 North Atlantic coast 

 from the eastern end of 

 Long Island north- 

 ward, and although 

 rare in shallow watei', 

 it is a1)undant at depths 

 ni twenty feet or more, 

 being especially com- 

 mon off Provincetown 

 or in Eastport Harbor. 

 The Purple Sea Ur- 

 chin, fArhcLcia jjinic- 

 tiiJatd, Fig. 31), a dark 

 brown or brownish-inirple sea urchin, is quite common on l^roken 

 rocky bottoms along our coast from Mexico to Cape Cod. The body 

 is globular and hemispherical, 

 and about one and three-quar- 

 ters inches in diameter. It is 

 protected by a skeleton formed 

 within the skin, and composed 

 for the most part of six-sided 

 calcareous plates arranged in 

 an orderly manner. The body 

 is covered with conical spines 

 of various lengths up to alDout 

 three-quarters of an inch. These 

 are found chiefly in five broad 

 radii regularly spaced around 

 the body, while between these 

 spiny areas one sees five nar- 

 row spaces almost devoid of 



spines. There ave five double rows of tube feet provided with ter- 

 minal suckers. TJiese arise in the spiny areas and may stretch 

 out so as to become longer than the spines themselves. At the 



Fig. 31; ITEl'LE SEA CRCHIN. 

 Cold Spring Harbor, Long Island Sound. 



